Add CONTRIBUTING.md (#229)

CONTRIBUTING.md

@@ -0,0 +1,31 @@
+# Contributing to faster-whisper
+
+Contributions are welcome! Here are some pointers to help you install the library for development and validate your changes before submitting a pull request.
+
+## Install the library for development
+
+We recommend installing the module in editable mode with the `dev` extra requirements:
+
+```bash
+git clone https://github.com/guillaumekln/faster-whisper.git
+cd faster-whisper/
+pip install -e .[dev]
+```
+
+## Validate the changes before creating a pull request
+
+1. Make sure the existing tests are still passing (and consider adding new tests as well!):
+
+```bash
+pytest tests/
+```
+
+2. Reformat and validate the code with the following tools:
+
+```bash
+black .
+isort .
+flake8 .
+```
+
+These steps are also run automatically in the CI when you open the pull request.

README.md

@@ -52,10 +52,6 @@ pip install --force-reinstall "faster-whisper @ https://github.com/guillaumekln/
 
 # Install a specific commit:
 pip install --force-reinstall "faster-whisper @ https://github.com/guillaumekln/faster-whisper/archive/a4f1cc8f11433e454c3934442b5e1a4ed5e865c3.tar.gz"
-
-# Install for development:
-git clone https://github.com/guillaumekln/faster-whisper.git
-pip install -e faster-whisper/
 ```
 
 ### GPU support